Written the documentation for the KeyName model.

Sources/Models/KeyName.swift

@@ -1,15 +1,30 @@
+/// This model is a concrete genetic definition that represents the following models: ``AmiiboSeries``, ``AmiiboType``, ``Character`` and ``GameSeries``.
 public struct KeyName {
+    
+    // MARK: Properties
+    
+    /// The key of the model.
     public let key: String
-    public let name: String?
+    
+    /// The name of the model.
+    public let name: String
+
 }
 
+// MARK: - Type aliases
+
+/// This model represents the series an amiibo belongs to.
+public typealias AmiiboSeries = KeyName
+
+/// This model represents the type an amiibo belongs to.
+public typealias AmiiboType = KeyName
+
+/// This model represents the character an amiibo is associated to.
+public typealias Character = KeyName
+
+/// This model represents the games series an amiibo is associated to.
+public typealias GameSeries = KeyName
+
 // MARK: - Decodable
 
 extension KeyName: Decodable {}
-
-// MARK: - Type aliases
-
-public typealias AmiiboType = KeyName
-public typealias AmiiboSeries = KeyName
-public typealias GameSeries = KeyName
-public typealias Character = KeyName